To control a mobile unit with high accuracy based on input images, it is necessary for a control system to recognize an object in the image as a target for behavior of the mobile unit. One approach is that the control system learns training data pre-selected by an operator prior to recognition. Specifically, the control system searches the input images to extract some shapes or colors therefrom designated as features of the target. Then, the control system outputs commands to make the mobile unit move toward the extracted target.
However, it is necessary for the operator to teach features such as shape or color of the target in detail to the control system and therefore preparation for that is a burden in terms of time and labor. In addition, since the control would be interrupted when the target goes off the input image, it is difficult to apply this approach to practical use.
An alternative approach is that a template for the target is prepared and during controlling the mobile unit the template is always applied to input images to search and extract shape and location of the target in detail. In this case, however, computational cost would become huge because a computer has to keep calculating the shape and location of the target. Furthermore, the calculation of searching the target may fall into a local solution.
Therefore, to control behavior of the mobile unit efficiently and flexibly, it is preferable to make the mobile unit move autonomously rather than utilizing supervised learning method as a target is specified beforehand. To achieve that, a method for recognizing the target autonomously and learning the location of the target is needed. In Japanese Patent Application Unexamined Publication (Kokai) No. H8-126981, image position recognition method in robot system is disclosed. According to the method, the target object is searched out autonomically even when the target object is missing out of input image due to the error. However, the method requires that work plane for recognizing images is painted with various colors prior to working, which is substantially time-consuming task.
In Japanese Patent Application Unexamined Publication (Kokai) No. H7-13461, a method for leading autonomous moving robots for managing indoor air-conditioning units is disclosed. According to the method, a target object for leading is detected through image processing and the robot is leaded toward the target. However, the method needs blowing outlets of air-conditioning units as target objects, which lacks generality.
Therefore, it is objective of the present invention to provide a behavior control apparatus and method for autonomously controlling a mobile unit based on visual information in practical application without the needs of a great deal of preparation or computational cost and limiting the type of target object.